Paper and process therefor



Patented Aug. 20, 1935 PAPER AND PROCESS THEREFOR George L. Bidwell,Riegelsville,

Pa., assignor to Riegel Paper Corporation, Riegelsville, N. J., a.corporation of New Jersey No Drawing. Application February 21, 1933,Serial No. 657,846

8 Claims.

This invention relates to paper, and more par ticularly to agrease-proof paper, either glazed like glassine or unglazed likeimitation parchment, which is to be converted into individualreceptacles for food products such as cakes and candies, drinking cups,containers to be used as finger bowls, and the like; and the objectthereof is to improve the surface on such paper so that one sheet willslip easily upon another.

In the manufacture of paper containers for use as finger bowls anddrinking cups and of paper receptacles for use in the candy and caketrade, it is the custom to die out shapes like circles, ovals, octagons,etc., in blocks, from which blocks "lifts are taken and placed in theform and there subjec-ted to heat and pressure so that when the pressureis released the sides of the cups are fluted" or crinkled'in clusters.These clusters of cups and/or receptacles must readily separate whenhandled in automatic dispensers, by waiters and waitresses inrestaurants, and by "piece workers in the candy and cake trade.

I have discovered that I can produce papers like glassine and imitationparchment having the slip-easy surface desired for the uses in question.

by applying hot wax to the wet paper web w ile it still retains amoisture content, usually not less than from to per cent, sufficient toallow the wax to satisfactorily penetrate the sheet. What is known aswet waxed" paper, that is to say, a waxed paper where all the Waxappears on the surface thereof, does not have the slip-easy"characteristics, nor, for the cup cake industry for example, is itdesirable to have a large quantity of wax on the-surface of the sheet.The wax used must, therefore, so penetrate the sheet as to leave on thesurface only the small amount sufficient to give the slip-easy" effect.

The wax, preferably a paramn wax-or an equivalent such, for example, aspetrosene, Montan, carnauba, ceresine, japan, wool, and beeswax, all ofwhich melt at a sufllciently low temperature, or a mixture of two ormore of these waxes-can be applied in any suitable way, as by spreadingit upon the paper sheet on the smoothing press or on one of the dryersin the usual battery of drying cylinders in a standard paper machine. Amore convenient and the preferred way, however, is to pass the sheetthrough a size press which is inserted at a point in the battery ofdrying cylinders where the sheet is dry enough so that it can be carriedthrough the press without crushing and the pan of which contains themelted wax preferably carried at a temperature somewhat higher than thetemperature of the sheet as it enters the size press, from to 210 F. forexample. The bottom roll of the press picks up' the melted wax andspreads it upon the sheet, while the top roll by its pressure thereonpartially 6 excludes the wax. The degree to which the paper sheet isimpregnated with the wax, and conse quently the degree of slip on thesurface of the finished paper, can readily be controlled by varying thetemperature of the wax and/or by regulat- 1 ing the pressure exerted bythe top roll of the press, the cooler the wax or the less the pressureof the top roll the greater the amount of the wax applied to the sheetand the greater the slip" produced, and vice versa. 7 iii The papersheet thus treated with Wax is then further dried, until its moisturecontent is reduced to some 60 to 68 per cent, and then impregnated witha plasticizer, preferably a solution composed of glycerin, cerelose (acommercial corn 20 sugar), sodium meta-silicate and water, in a secondsize press which is inserted at this point in the battery of dryingcylinders, substantially as disclosed in my co-pending application filedon May 10, 1932, Serial No. 610,506, upon which Let- 25 ters Patent No.1,914,799 were issued under date of June 20, 1933. The plasticizer thusapplied serves to cover the wax previously incorporated in the sheet andso to prevent the heat of the remaining drying cylinders from sobringing it to the surface 30 of the sheet as to give it an undesirableglaze,

foul the dryer felts, and, in the case ofglassine, interfere with itspassage through the supercalenders. The degree of slip" produced on thesurface of the finished paper can also be con trolled at this point,since the weaker the plasticizer solution used the more wax will appearon the surface of the sheet and the greater the slip produced. 40 In thecase of an unglazed imitation parchment paper, it is ready for shipmentas soon as it has been completely dried, so as to leave the usualmoisture content of approximately 6 per cent, and wound into rolls orcut into sheets; It requires no 45 further treatment since the waximpregnation and the plasticizing and therefore the contact with the hotdryers gives a sufficient finish. If the paper is to be glazed, as inthe case of glassine paper, it will next be dampened, preferably withthe alkali treated water and in the manner set forth in my saidco-pending application, and then finally run through the supercalenderswhere it is glazed and then it is that the full effects of the 55 scopeof the appended claims, without departing from the spirit or sacrificingthe substantial ad'- vantages thereof. I

What I claim as new and desire to secure by Letters Patent, is- I I 1.Paper of the type described treated when I partially'dried but retainingsome 70 to 75 per cent. of moisture with hot wax and when further driedbut retaining some to 68 per cent.

of moisture with a plasticizer, said paper being characterized by asurface slipping readily on another similar surface.

2. Paper of the type described treated when partially dried butretaining some '10 to '75 per cent. of moisture with melted paraflin waxcarried'at a temperature of some 160. to 210 F. and then-treated whenfurther dried but retaining some 60 to 68 per cent. of moisture with aplasticizing solution composed of glycerin, cerelose, sodiummeta-silicate and water.

3. A paper having incorporated therein during the drying of its webfirst a wax. and then a plasticizer and characterized by a surfaceslipping readily on another similar surface.

4. .A glazed paper having incorporated therein during the drying of itsweb first a wax and then a plasticizer, and finally dampened immediatelybefore being passed through the supercalendars with an alkali treatedwater.-

5. The process of making paper having a surface slipping readily on asimilar surface, which comprises as steps therein impregnating the wetpaper web while it still retains a. considerable part of its originalmoisture content first with a melted wax and then with a plasticizer.

6. The method of producing paper having a surface slipping readily on asimilar surface, which comprises as steps therein impregnating the sheetwhen partially dried but containing some 70 to. per cent. of moisturewith melted parafllnwax carried at a temperature of approximately to 210F. and when further dried but retaining some 60 to 68 per cent. ofmoisture with anaqueous solution containing glycerin, cerelose andsodium meta-silicate.

7. The process of making paper with a surface slipping readily on asimilar surface, which comprises as steps therein applying to the sheetwhile in course of manufacture and while being dried first a film of hotwax adapted to impregnate the sheet and then afilm containing aplasticizer adapted to so cover over the wax as to leave exposed on thesurface of the finished paper only sufilcient thereof to give it thedesired slip.

8. The method of making a paper having a surface slipping readily on asimilar surface, which comprises as steps therein impregnating the paperweb while it still retains a major part of its moisture content with amelted 'wax and controlling the degree of surface slip of the sheet bysubsequently treating it while still retaining a considerable part ofits moisture content with a solution containing a plasticizer.

GEO. L'. BIDWELL.

